From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.chen@nxp.com (Peter Chen) Date: Wed, 20 Jul 2016 17:40:24 +0800 Subject: [PATCH v3 1/6] binding-doc: power: pwrseq-generic: add binding doc for generic power sequence library In-Reply-To: <1469007629-31757-1-git-send-email-peter.chen@nxp.com> References: <1469007629-31757-1-git-send-email-peter.chen@nxp.com> Message-ID: <1469007629-31757-2-git-send-email-peter.chen@nxp.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add binding doc for generic power sequence library. Signed-off-by: Peter Chen Acked-by: Philipp Zabel --- .../bindings/power/pwrseq/pwrseq-generic.txt | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt diff --git a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt new file mode 100644 index 0000000..48bb3e1 --- /dev/null +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-generic.txt @@ -0,0 +1,48 @@ +The generic power sequence library + +Some hard-wired devices (eg USB/MMC) need to do power sequence before +the device can be enumerated on the bus, the typical power sequence +like: enable USB PHY clock, toggle reset pin, etc. But current +Linux device driver lacks of such code to do it, it may cause some +hard-wired devices works abnormal or can't be recognized by +controller at all. The power sequence will be done before this device +can be found at the bus. + +The power sequence properties is under the device node. + +Optional properties: +- clocks: the input clock for device. +- reset-gpios: Should specify the GPIO for reset. +- reset-duration-us: the duration in microsecond for assert reset signal. + +Below is the example of USB power sequence properties on USB device +nodes which have two level USB hubs. + +&usbotg1 { + vbus-supply = <®_usb_otg1_vbus>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_usb_otg1_id>; + status = "okay"; + + #address-cells = <1>; + #size-cells = <0>; + genesys: hub at 1 { + compatible = "usb5e3,608"; + reg = <1>; + + clocks = <&clks IMX6SX_CLK_CKO>; + reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; /* hub reset pin */ + reset-duration-us = <10>; + + #address-cells = <1>; + #size-cells = <0>; + asix: ethernet at 1 { + compatible = "usbb95,1708"; + reg = <1>; + + clocks = <&clks IMX6SX_CLK_IPG>; + reset-gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; /* ethernet_rst */ + reset-duration-us = <15>; + }; + }; +}; -- 1.9.1